Apparatus and method for zone-based positioning

ABSTRACT

An apparatus, and method of operating the same, include a system for indoor positioning and localization. The apparatus includes a first beacon having a beacon optical detector to receive an optical signal, and a beacon microcontroller. The apparatus includes a zone-positioning unit (ZPU) having an optical source configured to transmit the optical signal, and a ZPU microcontroller. The beacon microcontroller is configured to identify and decode the optical signal after receipt by the beacon optical detector to determine data related to a position of the ZPU. The beacon microcontroller is further configured to wirelessly communicate with the ZPU microcontroller to convey information to the ZPU including the data related to a position of the ZPU and a known position of the first beacon. The ZPU microcontroller is configured to determine a position of the ZPU based on the information received from the first beacon.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 63/007,629, filed on Apr. 9, 2020 and titled,“ZONE-BASED POSITIONING SYSTEM”, the contents of which are incorporatedherein by reference in its entirety.

FIELD OF THE TECHNOLOGY

The subject disclosure relates generally to indoor positioning andlocalization, including positioning of objects, people, and devices.

BACKGROUND OF TECHNOLOGY

The ability to measure absolute or relative position is an essentialcomponent for applications involving any human or robotic interactionwith the physical world. Positioning most clearly relates to vehicularnavigation (outdoors) but also includes indoor navigation, and objectlocalization and positioning for applications such as workplaceautomation and manufacturing. Positioning includes identifying theposition of an object as well as sustaining the object's position(tracking) when the object is in motion within a frame of reference.Outdoors, positioning is commonly realized by the adoption of GlobalNavigation Satellite System (GLASS); the use of cellular anchors, andinertial measurement units (IMUS). However, indoor solutions forproviding positioning and localization are less mature, being faced withchallenges due to limited coverage, inconsistent accuracy, the isolationof individual technical approaches, and many disparate applicationcontexts. Indoor environments are neither homogeneous in space nor inuse-case and is thus difficult to cover with a single positioningtechnology. Moreover, a contemporary tracked object or mobile device canhave many variants and can span changing spatial frames of reference,complicating the ability to provide a continuous positioning functionacross space and time.

Angle diversity positioning schemes, such as angle-of-arrival (AOA)schemes, and time synchronized positioning systems have shown to datethe best results for indoor positioning regardless of medium. Systemsthat use timing-based schemes, such as time-of-flight (TOF) ortime-of-difference-of arrival (TDOA), can be very accurate, but the needfor time synchronization makes them more difficult to implement across alarge number of devices and spaces. Commercial ultra-wideband and motioncapture camera systems provide great accuracy at the expense ofsystem-level cost and complexity, and gross knowledge of position.Light-based positioning is inherently directional and works well withAOA approaches.

Concurrently, the future of mobile devices is changing: the Cisco VNIMobile Forecast and Trends estimates that by 2022, there will be 1.1billion wearable devices globally. Fueled by “5G” and “edge”communications, an emerging market within personal wearable technologyincludes head-mounted devices for augmented and virtual reality (AR/VR),audio listening, and video recording. These include commercial entitiessuch as Microsoft HoloLens (AR), Bose Frames (audio), Snap Spectacles(camera), and others. Described herein are systems and methods ofimproved positioning systems which can be implemented within orassociated mobile devices.

SUMMARY OF THE TECHNOLOGY

The application, in various implementations, addresses deficienciesassociated with indoor positioning and localization. Disclosed herein isa novel personal zone-based positioning system that localizes a user viaa user device, anchored by an optical wireless communications linkbetween the user device and a beacon.

An example zone-based positioning system includes a first beacon placedat a known position within an environment at a given time. The firstbeacon includes a beacon optical detector configured to receive anoptical signal. The first beacon includes a beacon microcontroller. Thebeacon microcontroller is capable of wireless communication. The beaconmicrocontroller is also configured to demodulate the optical signal fromthe optical detector. The zone-based positioning system includes a zonepositioning unit (ZPU). The ZPU is either the positioned user device ora module attached to the positioned user device. In both cases,positioning the ZPU would position the user device. The ZPU includes anoptical source configured to transmit the optical signal and use opticalcommunication to communicate with the first beacon via the beaconoptical detector. The ZPU includes a ZPU microcontroller capable ofwireless communication. The ZPU microcontroller is configured tomodulate the optical source.

The beacon microcontroller is configured to identify and decode theoptical signal after receipt by the beacon optical detector to determinedata related to a position of the ZPU. The data includes an orientationof the ZPU. The beacon microcontroller is further configured towirelessly communicate with the ZPU microcontroller to conveyinformation to the ZPU including the data related to a position of theZPU and the known position of the first beacon. The ZPU microcontrolleris configured to determine a position of the ZPU based on theinformation received from the first beacon.

The ZPU may include a steerable system to direct the optical source toscan the environment for the first beacon as an optical target. Thesteerable system may include one or more of the following:micro-electromechanical system (MEMS), electro-optical system,holographic system, or plasmonics system. The ZPU may include agaze-tracking system, the gaze-tracking system configured to track aneye position of a user and direct the optical source based on the eyeposition of the user. The ZPU may include an inertial measurement unitto measure an orientation of the ZPU.

The ZPU may include a range sensor configured to measure a range fromthe ZPU to one or more of the following: the first beacon; a secondbeacon; another device; or an object. The range sensor may include oneor more of the following: light and radio frequency ranging via radiosignal strength, ultra-wideband signals, millimeter wave, radiofrequency, RADAR, time of flight, rotating laser, images, or LIDAR.

The zone-based positioning system may include an object, defined aswithout active components, positioned within the environment, and theZPU may be configured to transmit the optical signal to the object todetermine an orientation of the ZPU relative the object. The ZPU may befurther configured to measure the range between the ZPU and the object.The ZPU may be configured to determine a position of the object based onthe orientation of the ZPU and the range between the ZPU and the object.

The zone-based positioning system may include a transitive device,defined as with active components, positioned within the environment.The transitive device may include a transitive device optical detectorconfigured to detect the optical signal. The transitive device mayinclude a transitive device microcontroller capable of wirelesscommunication. The transitive device microcontroller may be configuredto identify and decode the optical signal after receipt by thetransitive device optical detector to an orientation of the ZPU relativethe transitive device. The transitive device microcontroller may beconfigured to wirelessly communicate with the ZPU to convey data theorientation of the ZPU relative the transitive device. These techniquesallow for relative positioning of objects and devices within thefield-of-view of the ZPU with respect to the ZPU. If the ZPU isabsolutely positioned, then the objects and devices positioned throughthese transitive means are also absolutely positioned.

The optical signal may be modulated by the ZPU microcontroller toinclude data related to a position of the ZPU, the data includingreal-time orientation measurements of the ZPU. The zone-basedpositioning system may include a second beacon positioned at a secondknown position within the environment. The second beacon may include asecond beacon optical detector configured to detect the optical signal.The second beacon may include a second beacon microcontroller capable ofwireless communication. The second beacon microcontroller may beconfigured to identify and decode the optical signal after receipt bythe second beacon optical detector to determine data related to anorientation of the ZPU. The second beacon microcontroller may be furtherconfigured to wirelessly communicate with the ZPU microcontroller toconvey information including the data related to a position of the ZPUand the known position of the second beacon to the ZPU. The ZPUmicrocontroller may be configured to determine a position of the ZPUbased additionally on the information received from the second beacon.

The zone-based positioning system may include a plurality of beaconspositioned at a plurality of known positions within the environment.

An example zone-based positioning system includes a first beaconpositioned at a known position within an environment. The zone-basedpositioning system includes a zone positioning unit (ZPU). The ZPUincludes an optical source configured to transmit an optical signal tothe first beacon, a range sensor configured to measure a range from theZPU to the first beacon; and a ZPU microcontroller configured toidentify the position of the first beacon based on the optical signal.The ZPU microcontroller is further configured to compute a position ofthe ZPU based on the range measurement from the ZPU to the first beacon,a transmission angle of the optical signal to the first beacon, and theposition of the first beacon.

The first beacon may include an identifiable optical signature. The ZPUmicrocontroller may be configured to detect the identifiable opticalsignature based on the optical signal. The ZPU microcontroller may beconfigured to determine the position of the first beacon based on theidentifiable optical signature and a database.

An example method of zone-based positioning includes providing a firstbeacon at a known position within an environment. The first beaconincludes a beacon detector configured to receive a signal. The firstbeacon also includes a beacon microcontroller capable of wirelesscommunication. The example method of zone-based positioning includesproviding a zone positioning unit (ZPU). The ZPU has a signaltransmission device and a ZPU microcontroller capable of wirelesscommunication. The ZPU microcontroller is configured to modulate thesignal transmission device. The example method of zone-based positioningincludes directing a modulated signal from the ZPU. The example methodof zone-based positioning includes decoding the modulated signal afterreceipt by the beacon detector to determine data related to a positionof the ZPU. The data includes an orientation of the ZPU. The examplemethod of zone-based positioning includes wirelessly communicatinginformation from the beacon microcontroller to the ZPU including thedata related to a position of the ZPU and the known position of thefirst beacon. The example method of zone-based positioning includesdetermining a position of the ZPU based on the information received fromthe first beacon.

The beacon detector may be a beacon acoustic detector configured toreceive an acoustic signal. The signal transmission device may be anacoustic source configured to transmit the acoustic signal. The beacondetector may be a radio frequency (RF) signal detector configured toreceive a RF signal. The signal transmission device may be an RF sourceconfigured to transmit the RF signal.

The example method of zone-based positioning may include measuring arange using a range sensor on the ZPU. The range may include a distancefrom the ZPU to one or more of the following: the first beacon; a secondbeacon; or an object. The example method of zone-based positioning mayinclude directing a modulated signal from the ZPU to an object todetermine data related to the ZPU position, the data including anorientation of the ZPU. The example method of zone-based positioning mayinclude measuring the range between the ZPU and the object using a rangesensor on the ZPU. The example method of zone-based positioning mayinclude computing a position of the object based on the data related tothe ZPU position and the range between the ZPU and the object.

The example method of zone-based positioning may include providing asecond beacon at a second known position within the environment. Thesecond beacon may have a second beacon detector configured to receive asignal, and a second beacon microcontroller capable of wirelesscommunication. The example method of zone-based positioning may includedecoding the modulated signal after receipt by the second beacondetector to determine data related to a position of the ZPU, the dataincluding an orientation of the ZPU. The example method of zone-basedpositioning may include wirelessly communicating information from thesecond beacon microcontroller to the ZPU including the data related to aposition of the ZPU and the known position of the second beacon. Theexample method of zone-based positioning may include determining aposition of the ZPU based additionally on information received from thesecond beacon.

The example method of zone-based positioning may include providing aplurality of beacons positioned at a plurality of known positions withinthe environment.

Any two or more of the features described in this specification,including in this summary section, may be combined to formimplementations not specifically described in this specification.

The details of one or more implementations are set forth in theaccompanying drawings and the following description. Other features andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the disclosedsystem pertains will more readily understand how to make and use thesame, reference may be had to the following drawings.

FIG. 1 is a schematic diagram of a zone-based positioning system in use,in accordance with the subject technology.

FIG. 2 is a block diagram of the components of the zone-basedpositioning system of FIG. 1.

FIG. 3A is a graph of orientations utilized for measurements within azone-based positioning unit, in accordance with the subject technology.

FIG. 3B is a perspective view of a zone-based positioning unit, inaccordance with the subject technology.

FIG. 4 is a three-dimensional orthographic view of a zone-basedpositioning system in use, in accordance with the subject technology.

FIG. 5 is a top view of the zone-based positioning system in use of FIG.4.

FIG. 6 is a schematic diagram of a zone-based positioning system in use,including a peripheral object, in accordance with the subjecttechnology.

FIG. 7 is a top orthographic view of a zone-based positioning system inuse, including a peripheral object, in accordance with the subjecttechnology.

FIG. 8 is a three-dimensional orthographic view of the zone-basedpositioning system in use of FIG. 7.

FIG. 9 is a perspective view of several time-based instances of using azone-based positioning unit as part of a zone-based positioning system,in accordance with the subject technology.

FIG. 10 is an overhead view of a zone-based positioning systemproliferated throughout an indoor space, in accordance with the subjecttechnology

FIGS. 11A-11B show graphs illustrating data collected from performancetesting using the zone-based positioning unit referenced in FIG. 3A-3B.

FIGS. 12, 13A, 13B, 14A, 14B, 14C, 15A, and 15B show graphs fortwo-dimensional simulated and experimental systems established to testdifferent configurations of a zone-positioning systems.

FIG. 16 depicts a graph showing position accuracies forthree-dimensional positioning.

FIGS. 17A-17B depict graphs showing position accuracies in simulated andexperimental models with and without the use of ranging.

FIGS. 18A-18B depict graphs showing transitive positioning errors insimulated and experimental models.

FIGS. 19A-19B depict graphs showing the impact of different transitivezone sizes.

DETAILED DESCRIPTION

Described herein are example implementations of zone-based positioningsystems and methods providing seamless, adaptable, and continuouspositioning and localization in indoor environments. In this regard, azone-based positioned system (ZPS) uses a positioning approach thatextends the mobile positioning volume around a user device, capable ofmeasuring an optical angle of departure and transmission of measuredangles over an optical signal. With a zone-based positioning system, apositioning unit locates a special beacon called a trust beacon. Theposition of the unit may then be determined based on its orientation,pointing angles, and range received at the beacon as an optical payloadand beacon coordinates at the time of reception. The positioned unitacquires the relevant data from the trust beacon via wireless backhaul,such as with radio frequency (RF). Zone-based positioning fuses threecore technologies in a novel way: active anchors, angle diversity, andoptical wireless communications (OWC).

With the zone-based positioning system, user devices anchor and positionthemselves with respect to the surrounding environment. The term anchor,referring to user devices, is defined herein as a calculated or knownposition within an environment such that the position can thereafter beused as a known variable in discerning the position of other devices orobject. The zone-based positioning system is aware that the user iswithin the space, but not where the user is in the space providing alayer of privacy to the user. A zone-based positioning system includesan infrastructure side, and a user-end. The infrastructure includescomponents that stay put within a physical environment, such as fixedlocation active devices called trust beacons that are provisioned to beself-aware of their respective locations within a building or space. Atthe user-end is a mobile or carried units by a person or robotconsisting of an inertial measurement unit, a low-power optical sourcefor optical wireless communications, amongst other components.

The ZPS described herein uses episodic communications between theuser-end device, defined herein as a zone-based positioning unit (ZPU),and a trust beacon. The initial communication is accomplished using aoptical signal. Within an optical signal payload are the real-timeorientation of the zone-based positioning unit, range information ifpresent, and instructions on how to communicate back to the ZPU. Oncethe trust beacon receives the communication payload, that is it iswithin the line-of-sight beam of the optical signal, it relays a messageback to the ZPU with the orientation angles it receives and with its owncoordinates appended. Finally, the ZPU computes positioning using thetrust beacon coordinates and the decoded angle between the ZPU andbeacon.

The subject technology overcomes many drawbacks associated with systemsfor indoor positioning and localization. In brief summary, the subjecttechnology relates to a zone-based positioning system involving userdevices and transitive devices anchoring and positioning themselves withrespect to a surrounding environment. The advantages, and other featuresof the systems and methods disclosed herein, will become more readilyapparent to those having ordinary skill in the art from the followingdetailed description of certain preferred embodiments taken inconjunction with the drawings which set forth representative embodimentsof the present invention. Like reference numerals are used herein todenote like parts. Further, words denoting orientation such as “upper”,“lower”, “distal”, “latitudinal”, “longitudinal”, and “proximate” aremerely used to help describe the location of components with respect toone another. For example, an “upper” surface of a part is merely meantto describe a surface that is separate from the “lower” surface of thatsame part. No words denoting orientation are used to describe anabsolute orientation (i.e., where an “upper” part must always be ontop).

Referring now to FIG. 1, an example zone-based positioning system 100 isshown. The zone-based positioning system includes a zone-basedpositioning unit (ZPU) 104. The ZPU 104 is a user device that positionsitself within an environment 110 by using angle-of-departure (andoptionally ranging) to estimate its position in two-dimensional andthree-dimensional space. The ZPU 104 can be a headset worn on a user102. The ZPU 104 may also be a personal device such as a mobile phone, atablet computer, a device affixed to a robot or another vehicle, or alike device.

The ZPU 104 includes a narrow field-of-view optical source whichtransmits an optical signal 106. The optical signal 106 may bedirectional. The ZPU 104 episodically communicates via optical signal106 with a trust beacon 108. Trust beacons 108 are fixed locationsbeacons commissioned with a known set of coordinates. The trust beacon108 is located by the ZPU 104 within a field-of-view of the transmittedoptical signal 106. The optical signal 106 is modulated with the ZPU 104current angular orientation 112. Thus, when the trust beacon 108receives the optical signal 106, that is the beacon is withinline-of-sight of the ZPU transmitter, the trust beacon 108 can confirmreceipt of the signal 106 and angular information 112 by a wireless backchannel, such as RF: Bluetooth Low Energy or WiFi. In some instances,range information can also be derived based on the signal 106 modulationonce the signal 106 is received by the trust beacon 108.

Because of a trust beacon's 108 role of position fixing (nullingaccumulated position drift error) and orienting, trust beacons 108 maybe placed throughout a navigated space, but also with higher frequencyin areas in which higher precision positioning is desired. Inexpensivecomponents enable proliferation of trust beacons 108 throughout a space110 at a low system cost. Trust beacons 108 may communicate in ahierarchical or peer-to-peer mode without continuous connection to abroader network, enhancing location privacy. Trust beacons 108 arecompatible with a range of ZPUs 104 of varying complexities to enabledifferent performance levels.

The optical signal 106 between the ZPU 104 and the trust beacon 108 isaccomplished using a narrow field-of-view optical source such as alow-powered laser or LED, or other optical source. As mentioned prior,the optical signal 106 include a payload transmitted from the ZPU 104.The optical signal 106 payload includes the current orientation 112 ofthe ZPU 104 and instructions on how to communicate back to the ZPU 104via a wireless backchannel. The instructions include information to makea connection, such as an IP address, protocols, standards, and so on.Range information 114, such as a range between the ZPU 104 and the trustbeacon 108 may also be collected by the ZPU 104 through use of a rangesensor. Once the trust beacon 108 receives the payload, it relays asignal back to the ZPU 104 with the orientation 112 it receives and withthe trust beacon 108 coordinates appended. Finally, the ZPU 104 computesa ZPU 104 position using the trust beacon 108 coordinates, orientation112 including inertial measurement unit (IMU) measurements, and range114.

For one-dimensional computation of a ZPU 104 position, a height 116 ofthe ZPU 104 is known. A reasonable assumption of the height 116 can bemade where the ZPU 104 is head-mounted on a user 102, such as on glassesor a headset, or a fixed-height automation robot. Range information 114is not required to calculate the ZPU 104 position in the environment110.

For instance, a microcontroller unit on a ZPU 104 is configured tocalculate a ZPU 104 position. The ZPU 104 is located at a height 116above the lower surface of the environment 110 (e.g., a floor), referredto herein as H or Y_(H). A trust beacon 108 also has a height 122,referred to herein as B. As such the ZPU 104 and trust beacon 108 havetwo-dimensional locations within an environment 110, represented bycoordinates (X_(H), Y_(H)) and (X_(B), Y_(B)) respectively, where theZPU 104 height 116, Y_(H), is known. The ZPU 104 and trust beacon 108are located a planar distance 114 away from each other, referred toherein as d. A vertical component 118 of that distance, referred toherein as Δy, between the ZPU 104 and the trust beacon 108 can becomputed through the following equation:Δy=Y _(B) −H  (1)

The horizontal component 120 of planar distance 114, referred to hereinas Δx, from the ZPU 104 to the beacon 108 is thus computed through thefollowing equation:

$\begin{matrix}{{\Delta x} = \frac{\Delta y}{\tan(\phi)}} & (2)\end{matrix}$

where φ is a pitch angle 112 between the ZPU 104 and the beacon 108.

Having calculated the horizontal component 120 of planar distance 114,the horizontal coordinate of the ZPU 104 can also be calculated throughthe following equation:X _(H) =X _(B) −Δx  (3)

The coordinates of the ZPU 104, represented herein as X_(H), Y_(H), arethus accounted for.

For two-dimensional computation of a ZPU 104 position, that is, wherethe height of the ZPU 116 is unknown, a ranging device is equipped tothe ZPU 104. Still referring to FIG. 1, ZPU 104 and trust beacon 108have locations within an environment 110, represented by coordinates(X_(H), Y_(H)) and (X_(B), Y_(B)) respectively, where the ZPU 104coordinates are unknown. The ZPU 104 and trust beacon 108 are located aplanar distance 114 away from each other, referred to herein as d. Thevertical component 118 of that distance between the ZPU 104 and thetrust beacon 108 can be represented through the following equation:Δy=d sin(φ)  (4)

As such, the height 116 of the ZPU 104 from the surface of theenvironment 110 can be computed using the beacon 108 height coordinate122 and the vertical component 118 through the following equation:Y _(H) =Y _(B) −Δy  (5)

In this regard, the horizontal component 120 of planar distance d,referred to herein as Δx, from the ZPU 104 to the beacon 108 isrepresented through the following equation:Δx=d cos(φ)  (6)

Where φ is a pitch angle 112 between the ZPU 104 and the beacon 108,represented as 112. Having calculated the horizontal component 120 ofthe distance d from the ZPU 104 to the beacon 108, the horizontalcoordinate of the ZPU 104 can also be calculated through the followingequation:X _(H) =X _(B) −Δx  (7)

As such, the ZPU 104 coordinates, (X_(H), Y_(H)), are accounted for.Computation for the third-dimension is described later.

Referring now to FIG. 2, the components of the zone-based positioningsystem 100 of FIG. 1 are shown. The ZPU 104 includes an inertialmeasurement unit (IMU) 206. The IMU 206 measures the ZPU 104 specificforce, angular rate, and orientation of the ZPU 104 using a combinationof accelerometers, gyroscopes, and magnetometers. A configuration of theIMU 206 includes one accelerometer, one gyroscope, and one magnetometerper axis for each of the three principal axes as explained withreference to FIG. 3: pitch, roll, and yaw. The ZPU 104 also includes amicrocontroller unit (MCU) 210. The MCU 210 contains one or more centralprocessing units and memory. The MCU 210 measures the real time force,angular rate, and orientation of the ZPU. The MCU 210 is also capable ofwireless communication. Wireless communication includes optical wirelesscommunication. Wireless communication also includes directional wirelesscommunication. In this regard, the MCU 210 may include a radio-frequencymodule to transmit or receive radio signals. As such, the MCU 210 cancommunicate with the trust beacon without needing line-of-sightcommunications 108.

The MCU 210 is also capable of determining a position of the ZPU 104through communication with the trust beacon 108. From the trust beacon108, the MCU 210 receives data including an orientation 112 of the ZPU104 and receives beacon 108 coordinates to thereafter compute a locationof the ZPU 104 in the environment 110 as explained herein.

The MCU 210 may also compute a beacon 108 position based on an opticalsignal 106, using a narrow field-of-view optical source 216 such as alow-powered laser or LED, or other optical source such as a modulatedlaser beam, capable of transmitting an optical signal 106 to the beacon108. In this regard, the ZPU 104 includes an optical driver 212, forexample a laser driver, and the narrow field-of-view optical source 216,for example a laser diode. The optical driver 212, controlled by the MCU210, provides a current to the narrow field-of-view optical source 216to control the optical output while protecting the narrow field-of-viewoptical source 216 from over current conditions. The optical driver 212converts electrical signals to optical signals. In some implementations,the optical driver 212 may include a resistor and amplifier where theamplifier measures the voltage across the resistor and controls outputin a feedback loop to maintain the resistor voltage as close as possibleto a control voltage. Direct modulation of the narrow field-of-viewoptical source 216 can be completed by altering the control voltage.External modulation of the narrow field-of-view optical source 216 canbe completed through use of a light modulator. The narrow field-of-viewoptical source 216 is continually modulated by the MCU 210 with thereal-time measured orientations so that whenever the optical signal 106reaches a trust beacon 108, the trust beacon 108 can initiate a returnmessage 226 and the ZPU 104 can position itself with the new informationprovided by the trust beacon 108. The payload of the optical signal 106is relatively small such that on-off-keying at low intensities issufficient, though other modulation formats are also sufficient.

The modulated narrow field-of-view optical source 216 emits the opticalsignal 106 in a line-of-sight nature, allowing the optical signal 106 tobe treated as a ray, such that the pitch 112 between the ZPU 104 andbeacon 108 is relevant to ZPU 104 positioning. The modulated opticalsignal 106 is received by a beacon detector 222, such as a photodetectoror optical receiver, on the trust beacon 108 wherein the optical signal106 is converted into an electrical current. In other implementations,the narrow field-of-view optical source 216 emits an optical signal 106toward an identifiable optical signature on a trust beacon 108. The MCU210 is configured to detect the identifiable optical signature, based onthe optical signal 106, and determines the position of the beacon 108based on the identifiable optical signature and a database. Theidentifiable optical signatures include formats such as quick response(QR) code, barcodes, or other static or dynamic optical codes.

The trust beacon 108 includes a MCU 224 to demodulate or decode theoptical signal from the beacon detector 222. The MCU 224 identifies anddecodes the optical signal 106 after receipt by the beacon detector 222to determine data related to the ZPU 104, such as the orientation 112 ofthe ZPU 104 relative the trust beacon 108. The MCU 224 thereafterwirelessly communicates a return message 226 with the MCU 210 of the ZPU104 to transmit the trust beacon location 108 in the environment and thedata related to the ZPU 104, such as the orientation 112 of the ZPU 104.This return message 226 is completed through a wireless communications,such as a radio frequency, backhaul, or back channel Where the height116 of the ZPU 104 is known, the MCU 210 thereafter computes a ZPU 104location within the environment.

Where the height 116 of the ZPU 104 is unknown, the ZPU 104 includes arange sensor 208 to measure a planar, or Euclidean, distance between theZPU 104 and the trust beacon 108. The range sensor 208 may include lightand radio frequency ranging via radio signal strength, ultra-widebandsignals, millimeter wave, radio frequency, RADAR, time of flight,rotating laser, images, or LiDAR. Resulting ranging information may beappended to the optical signal 106 and received by the trust beacon 108,wherein the range information is relayed back to the ZPU 104 through areturn message 226.

In some implementations, the ZPU 104 may also include a steerable system214 to direct the optical signal 106 to scan the environment 110 for thebeacon 108 as an optical target. The steerable system 214 may include asteerable micro-electromechanical system, electro-optical system,holographic system, or plasmonics system.

The ZPU 104 may also include a gaze-tracking system 228 configured totrack an eye position of a user 102 or a line of sight of the user 102.The MCU 210 may direct the IMU 206 to measure an orientation 112 basedon the eye position of the user 102. In this regard, the ZPU 104 maythereafter transmit from the narrow field-of-view optical source 216 anoptical signal 106 based on the direction of the user 102 eye position.

In some implementations, the ZPU 104 may include an acoustic sourceconfigured to relay an orientation or range of the ZPU 104. In thisregard, the beacon detector 222 may include an acoustic detector such asa geophone, hydrophone, microphone, pickup, seismometer, or soundlocator. Thus, the beacon detector 222 is configured to receive anacoustic signal from ZPU 104.

In some implementations, the ZPU 104 may include a beam formed radiofrequency source configured to relay an orientation or range of the ZPU104. In this regard, the beacon detector 222 may include a radiofrequency signal detector such that the beacon detector 222 isconfigured to receive a radio frequency signal from the ZPU 104.

FIG. 3A-3B show the components and orientations of the ZPU 104implemented within a pair of glasses, allowing it to be worn on the headof a user, but could be employed with different structural components inother instances. As mentioned prior, the ZPU 104 includes a narrowfield-of-view optical source 216 to transmit an optical signal 106 tothe trust beacon 108, and an MCU 210.

For sake of explanation of orientation, a reference point 302 isincluded on ZPU 104. As such, the ZPU 104 orientation relative to thereference point 302 is used to compute the ZPU 104 location in anenvironment 110. The orientation values measured by the IMU 206 arepitch 304 and yaw 306 angles, φ_(i) and θ_(i) respectively where irefers to a trust beacon 108. The IMU 206 may also measure a roll 308 ofthe ZPU 104, though roll 308 is negligible where the ZPU 104 sitssymmetrically on a user 102.

Referring now to FIG. 4 and FIG. 5, a side orthographic view and a topview of FIG. 4 are shown, the system having two trust beacons 404 and408. Zone-based positioning system 400 includes a ZPU 104 worn by a user102, or a personal device such as a mobile phone, iPad, a device affixedto a robot or another vehicle, or a like device. The ZPU 104 caninteract with the trust beacons 404, 408. For explanatory purposes,trust beacon 404 is acting as an origin in the X, Y plane relative athree-dimensional coordinate system. Therefore, trust beacon 404 islocated at coordinates (0, 0, Z₁) with respect to a (X, Y, Z) coordinatesystem. Trust beacon 408 has three-dimensional coordinates of (C, 0, Z₂)with respect to the same (X, Y, Z) coordinate system, where C representsa planar distance between trust beacon 404 and 408. Trust beacons 404,408 are fixed locations beacons commissioned with information of theirrespective coordinates. The trust beacons 404, 408 are located by theZPU 104 within a field-of-view of a narrow field-of-view optical source216 included within the ZPU 104. As mentioned prior, the optical source216 is modulated and transmits an optical signal 106 based on itscurrent orientation with respect to the target trust beacon 404, 408.Then the trust beacon 404, 408 confirms reception of the angularinformation by a wireless back channel, such as Bluetooth Low Energy,WiFi or other communications medium, including appending the trustbeacon 404, 408 coordinates.

In this implementation, measured values at the ZPU 104 headset are pitchand yaw angles, φ_(i) and θ_(i), where i refers to either trust beacon404, 408. When subjected to uniform noise, pitch and yaw angles arerepresented as {circumflex over (φ)}_(t)=φ_(i)+φ_(n) and

=θ_(i)+θ_(n). The roll of the ZPU 104 is negligible as the ZPU 104 sitssymmetrically on the user 102. Due to no prior reference headingdirection, yaw is measured from a fixed but unknown vector v, referredto herein as 506. In the system 400, two trust beacons 404, 408 areemployed, the beacons 404, 408 placed a planar distance, C, away fromone another laterally, the distance referred to herein as 406, tocalibrate yaw, θ. The trust beacons 404, 408 are located a radialdistance away from ZPU 104, represented herein as R₁, 412, and R₂, 418.

Pitch and yaw are measured respective to the horizon and thus can bepre-calibrated. From the pitch angles φ, referred to herein as 414 and420; known ZPU height 116; and beacon 404, 408 coordinates, horizontalcomponents of planar distances 412, 418, referred to herein as A and B,or 416 and 422 respectively, between the user 102 and the trust beacons404, 408 can be computed using the following equations:

$\begin{matrix}{{B = \frac{\Delta }{\tan\left( \varphi_{1} \right)}},{A = \frac{\Delta }{\tan\left( \varphi_{2} \right)}},} & (8)\end{matrix}$

where φ₁ is angle 414, φ₂ is angle 420, and Δ is the difference betweenthe ZPU 104 height, H, represented herein as 116, and the height of thetrust beacon 404, 408, referred to herein as Z. H is known in somescenarios, and the height Z of the trust beacon 404, 408 is communicatedvia a return message 226 from the trust beacon 404, 408 to the ZPU 104.

The yaw aspect of the ZPU 104, θ_(A), referred to herein as 528, canthereafter be computed. Beacons 404, 408 are located an angle θ_(C),referred to herein as 526, away from one another relative the ZPU 104location. Beacon 404 is located at an angle θ₂, referred to herein as524 away from vector 506. Beacon 408 is located an angle θ₁, referred toherein as 522, away from vector 506. θ_(C) can be represented as thedifference between θ₂ and θ₁. As such, the yaw of the ZPU 104 can becomputed using the following equation:

$\begin{matrix}{\theta_{A} = {si{n^{- 1}\left\lbrack \frac{A\mspace{11mu}{\sin\left( \theta_{C} \right)}}{c} \right\rbrack}}} & (9)\end{matrix}$

Although the distance between trust beacons 404 and 408, C, is definedand known, confining C may force ΔABC to not converge, resulting in ascenario where no triangle solution is possible from measured data. Inthat case, lateral displacement Ĉ between trust beacons 404 and 408 canbe computed using the following equation:Ĉ=[A ² +B ²−2AB cos(θ_(C))]^(1/2)  (10)

From θ_(A), the coordinates of the ZPU 104, {circumflex over (x)} and ŷ,can be estimated through the following equations:{circumflex over (x)}=B cos(θ_(A)),ŷ=B sin(θ_(A))  (11)

For the three-dimensional scenario, where the ZPU 104 height 116 isunknown, another measurement in the form of range is required. ZPU 104may include a range sensor 208, which may be provided in a multitude ofways with different accuracies: light and radio frequency ranging viaradio signal, strength, ultra-wideband signals, millimeter wave, radiofrequency, RADAR, time of flight, rotating laser, images, or LiDAR. WithLiDAR for example, a radial distance between a trust beacon 404, 408 andthe ZPU 104, R_(i) is measured, where i refers to a trust beacon 404,408. A and B are now calculated from R₁ and R₂ using the followingequations:B=R ₁ cos(φ₁),A=R ₂ cos(φ₂)  (12)

The height of the ZPU 104 can be computed using the known height Z ofeither trust beacon 404, 408 through the following equation:{circumflex over (z)} ₁ =Z−B tan(φ₁),{circumflex over (z)} ₂ =Z−Atan(φ₂)  (13)

After the height of the ZPU 104 is computed in a three-dimensionalscenario, equations 8-12 thereafter apply. Note, the height of the ZPU104 with respect to different trust beacons 404, 408 can be averaged fora height estimate. In fact, in a system 400 with a plurality of beacons,any number of beacon measurements encountered can be averaged for heightimprovements over time using the following equations:

$\begin{matrix}{{\overset{\hat{}}{z}}_{i} = {Z - {R_{i}{\sin\left( \varphi_{i} \right)}}}} & (14) \\{\overset{\hat{}}{Z} = {\frac{1}{N}{\sum\limits_{i = 1}^{N}{\overset{\hat{}}{z}}_{i}}}} & (15)\end{matrix}$

where N is the total number of beacons with measurement data, R_(i) isthe radial distance between the trust beacon 404, 408 and the ZPU 104measured with a ranging sensor, and φ_(i) is the angle related to theradial distance measured by the ZPU 104. In practice, R_(i) is subjectedto error, ∈_(R).

Referring now to FIG. 6, a zone-based positioning system 600 is shownincluding an object 610. The zone-based positioning system 600 includesa ZPU 104. As with zone-based positioning system 100, an optical signal106 is transmitted between the ZPU 104 and trust beacon 108, including apayload transmitted from the ZPU 104. In this regard, the optical signal106 includes the current orientation 112 of the ZPU 104 and instructionson how to communicate back to the ZPU 104 via an RF backchannel. Rangeinformation, such as a range between the ZPU 104 and the trust beacon108 may also be collected by the ZPU 104 through use of a range sensor.Once the trust beacon 108 receives the payload, it relays a signal 106back to the ZPU 104 with the orientation it receives and with the trustbeacon 108 coordinates appended. Finally, the ZPU 104 computes a ZPU 104position using the trust beacon 108 coordinates, orientation 112including IMU measurements, and range 114.

A key feature of an angle-of-arrival sensor aboard the ZPU 104, such asan IMU 206, is that once the ZPU 104 is localized, it can position otherobjects 610 within its “zone” radius and field of view, referred toherein as transitive positioning. Transitive positioning is accomplishedby reusing the same narrow field-of-view optical source 216 and a rangesensor 208 on the ZPU 104 used to target trust beacons 108 to alsotarget secondary peripheral objects 610. In this regard, the ZPU 104 isused as a reference point, directing an optical communication to otherobjects. Transitive positioning is analogous to the use of a theodolite,which can utilize distance and an angle to well-known positions toestimate the range and bearing to other objects 610.

Object 610 can be passively or actively positioned. In the active case,object 610 is a transitive device. Therein, angles are communicatedsimilar to the ZPU 104 and trust beacon 108 interaction. In this regard,the object 610 includes a transitive device optical detector, such as aphotodetector, to detect the optical signal 612 from the ZPU 104, and atransitive device MCU capable of wireless communication. Thus, theobject 610 has the same components as a trust beacon 108 as explainedprior. The transitive device MCU is configured to identify and decodethe optical signal 612 after receipt by the transitive device opticaldetector to determine data related to a position of the ZPU 104, such asan orientation of the ZPU 104. In this case, the angles of the ZPU 104relative the object 610 are decoded by an active receiver. Thetransitive device MCU is configured to wirelessly communicate with theZPU 104 to convey the measured orientation of the ZPU 104, data relatedto a position of the object 610, and range measurements.

In the passive case, the user 102 targets and identifies the object 610with the ZPU 104 to position the object 610. As such, the ZPU 104 isconfigured to transmit the optical signal 612 to the object 610 todetermine the ZPU 104 orientation relative the object 610. The ZPU 104is configured to measure the range between the ZPU 104 and the object610. The ZPU 104 is configured to determine a position of the object 610based on the orientation relative the object 610 and the range betweenthe ZPU 104 and object 610.

Referring now to FIGS. 7-8, a top orthographic view and a sideorthographic view of a zone-based positioning system 700 are shown, thesystem 700 having a trust beacon 108 and an object 610. The system 700may be bound by a coordinate system having an x-axis 728 and a y-axis730, where the trust beacon 108 is situated at the origin forexplanatory purposes. Object 610 is located at a vertical position 718,ŷ_(t), and a horizontal position 716, {circumflex over (x)}_(t), withinthe coordinate system. A yaw angle, θ_(D), referred to herein as 711,between a trust beacon 108 and the object 610 is measured at the ZPU 104similarly to how θ_(C) was measured with respect to FIG. 5. FIGS. 7-8show the transitive geometry with respect to the direct positioning zone726 for the case where yaw is positive, 180°>θ_(D)>0°, and for onequadrant of the object zone 724. When yaw is negative, the geometry isflipped. As such, computation may be achieved for a single object zone724 quadrant; the other three quadrants computed through coordinatetransformations.

The planar distances between the object 610, beacon 108, and ZPU 104make up triangle ΔTBD. T is the planar distance between the ZPU 104 andthe object 610, referred to herein as 712. B is the planar distancebetween the ZPU 104 and the beacon 108, referred to herein as 120. D isthe planar distance between the trust beacon 108 and the object 610,referred to herein as 720.

In the case where the ZPU 104 height 116 is unknown, ranging informationis used. T and B are calculated as A and B were calculated withreference to zone-based positioning system 400 using equation 12. Assuch, the radial distance R_(T), referred to herein as 842, between theZPU 104 and the object 610 is used with equation 12. Similarly, theradial distance R₁, referred to herein as 114, between the ZPU 104 andthe trust beacon 108 is used with equation 12. D and θ_(T), referred toherein as 714, are calculated using the Law of Cosines and Law of Sinesrespectively using the following equations:

$\begin{matrix}{D = \left\lbrack {T^{2} + B^{2} - {2{TB}\;{\cos\left( \theta_{D} \right)}}} \right\rbrack^{1/2}} & (16) \\{\theta_{T} = {\sin^{- 1}\left\lbrack \frac{T\;{\sin\left( \theta_{D} \right)}}{D} \right\rbrack}} & (17)\end{matrix}$

The angle between the trust beacon 108 and the ZPU 104, θ₃, bound by thex axis 728, can be computed based on the ZPU 104 location, the anglereferred to herein as 708:

$\begin{matrix}{\theta_{3} = {\tan^{- 1}\left\lbrack \frac{\overset{\hat{}}{x}}{\overset{\hat{}}{\gamma}} \right\rbrack}} & (18)\end{matrix}$

For the 180°>θ_(D)>0° case, the constraint of θ₄=90°−θ_(T)−θ₃ can beintroduced to estimate the object location, θ₄ is the angle formed bythe y-axis 718 and D, the angle referred to herein as 722, Thus, theobject 610 coordinates, {circumflex over (x)}_(t), ŷ_(t), can becomputed using the following equations:{circumflex over (x)} _(t) =D sin(θ₄),ŷ _(t) =D cos(θ₄)  (19)

The z coordinate estimate of the object 610, {circumflex over (z)}_(t),is based on the pitch angle, φ_(T), referred to herein as 844, betweenthe ZPU 104 and the object 610. Depending on whether φ_(T) is positiveor negative, the following equations can be used to compute the object zcoordinate:

$\begin{matrix}{{\Delta\; T} = {{R_{T}{\sin\left( \varphi_{T} \right)}}}} & (20) \\{\overset{\hat{}}{Z} = \left\{ \begin{matrix}{{z + {{\Delta T}\mspace{20mu}{if}\mspace{20mu}\phi_{T}}} > 0} \\{{z - {{\Delta T}\mspace{20mu}{if}\mspace{20mu}\phi_{T}}} < 0}\end{matrix} \right.} & (21)\end{matrix}$

where ΔT is the height 850 of the object 610.

Referring now to FIG. 9, an example zone-based positioning system 900 isshown including several time instances 902, 904, 906, 908 of ZPU 104orientations. The ZPU 104 in zone-based positioning system 900 includesa steerable system to direct the optical source to scan the environment901. The ZPU 104 can continuously scan the environment 901 in eachdirection, but represented as vertical direction for simplicity in FIG.9, as progressing through the several instances 902, 904, 906, 908 ofZPU 104 orientations. The ZPU 104 therein may alternatively include agaze-tracking system to track an eye position of a user 102 and directthe optical source based on the eye position of the user 102. In thisregard, the ZPU 104 optical source may progress through severalinstances 902, 904, 906, 908 based on a steerable system or the eyeposition of the user 102.

As mentioned prior, the ZPU 104 measures orientation with respect to thereference axes 304, 306, 308 of FIG. 3A and then encodes thatinformation onto the optical payload of its narrow field-of-view opticalsource 216 in preparation to hit a target and complete a data transfer.This transfer engages when a user 102 directs the optical signal 106onto a trust beacon 108, such as in instance 906. Also within the narrowoptical signal 106 payload is continuously updated range information, ifpresent, and instructions on how to communicate back to the ZPU 104 viaan RF backchannel. The narrow field-of-view optical source 216 iscontinually modulated so that once the optical signal 106 hits a targettrust beacon 108 receiver, the trust beacon 108 can initiate a returncall to the ZPU 104 with updated measurements. The signal between theZPU 104 and the trust beacon 108 is null at the photodetector of thetrust beacon 108 until the narrow field-of-view optical source 216targets the trust beacon 108 with its pointing angles, φ_(t), at a giventime instance t. As such, real-time orientation measurements of the ZPU104 are transmitted. Once the trust beacon 108 receives the payload, itrelays a message back to the ZPU 104 with the orientation angles itreceived but also appending the trust beacon 108 coordinates. Finally,the ZPU 104 computes a ZPU 104 position using the trust beacon 108coordinates and measured angles and ranges. Once the ZPU 104 computes aZPU 104 position after making contact with the trust beacon 108 as ininstance 906, the ZPU 104 can thereafter compute the location of theobject 610, after scanning the object 610 with the narrow field-of-viewoptical source 216, as seen in instance 908. This can be done asexplained prior with reference to FIGS. 7-8.

Referring now to FIG. 10, an overhead view of an example zone-basedpositioning system 1000 proliferated through an indoor space 1001, inaccordance with the subject technology, is shown. As mentioned withother zone-based positioning systems described herein, zone-basedpositioning system 1000 includes a plurality of trust beacons 108positioned through the interior of indoor space 1001. A network of users102 travel throughout indoor space 1001, each user 102 equipped with aZPU 104 in accordance with the subject technology. As such, each ZPU 104in zone-based positioning system 1000 may compute a respective ZPU 104location. Each ZPU 104 in zone-based positioning system 1000 maycommunicate with one another and to a central control system 1020regarding the respective ZPU 104 locations. In this regard, real-timepositioning of users 102 throughout an indoor environment 1001 can betracked and optimized. The indoor space 1001 may also include objects610, wherein users 102 can orient a respective ZPU 104 toward the object610 to determine the object 610 location.

FIG. 11 shows graphs 1102(a) and 1102(b) illustrating data collectedfrom performance testing using the ZPU 104 referenced in FIG. 3A-3B. Theexperimental prototype ZPU 104 was a headset with a 5 mW, 650 nm redTTL-transistor-transistor logic-laser (Adafruit part no. 1056) and anAdafruit variant ESP32 MCU fitted to a pair of Bose Frames. The BoseFrames are a commercial off-the-shelf audio AR headset with built-ininertial measurement units 206 including an accelerometer, gyroscope,and magnetometer. The Bose Frames API uses these sensors to compute aquaternion that converts to Euler angles: pitch, roll, and yaw as shownin FIG. 3A. The laser is driven using the UART communication protocol,which is an OOK modulation common with MCUs, at a baud rate of 115.2kbps. The trust beacon is a Thorlabs PIN PD (part no. PDA36A) withanother ESP32 MCU.

The prototype ZPU 104 is mounted on an optical breadboard for stability,which, in turn, is fastened to a sturdy tripod. The tripod enablesadjustment of height, pitch, and yaw reliably and quickly. The entiresystem is placed within the coverage of a motion capture camera system(Optitrack) to measure the coordinates of the ZPU down to millimeters.The trust beacons are placed on an elevated cage.

For supporting accurate positioning, repeatability of measurements takenafter various translations and rotations of the ZPU 104 are of moment,as shown in graphs 1102(a) and 1102(b). Experimentation revealed that inthe case of a fixed position (no motion), the ZPU 104 reveals consistentmeasurements in returned pitch, roll, and yaw when exposed to motions,confined to movements less than 10 m from starting location andaccelerations less than 9.8 m/s² (gravity).

In this experimentation, the pitch, roll, and yaw of the ZPU 104 weremeasured at a known location. The Bose Frames were moved erratically(e.g., a motion that is jerky, smooth, quick, elaborate, small, large,etc.) and were placed back at the knock location to remeasure the pitch,roll, and yaw angles. This procedure was repeated for 20 samples. FIGS.11A-11B show the raw measured angles. With the pitch and roll, themeasurements remained consistently within ±0.5° of the mean, whereaswith the yaw, the measurements drift upwards. This is due to pitch androll measured relative to gravity and the horizon and yaw having noreference point. The lack of yaw reference can be cured by calibratingbetween two points. Graph 1102(b) shows that when the difference betweentwo yaw measurements is taken, by rotating the device between two knownlocations, i.e., beacons, the angle differences between the measurementsare now consistent with the pitch and roll measurements and within ±0.5°of the mean. As such, the ±0.5° error is simulated herein as noise withrespect to angles φ_(n) and θ_(n).

Yaw accuracy may also be increased by using the yaw angle difference ofa MEMS steerer, as referenced above, which can bring the noise error toless than 0.01° discussed in further detail below. It is possible toreference magnetic north using the magnetometer, but the technique isnot, reliable indoors. Higher-end EMUs 204 and different algorithmsbeyond the commercial off-the-shelf Bose Frame system for calculatingpitch and yaw may be implemented.

Referring now to FIGS. 12-15, results are displayed for two-dimensionalsimulated and experimental systems established to test differentconfigurations of a zone-positioning systems to compare to otherlight-based AOA indoor positioning approaches. The conditions simulateddemonstrate the effects of different configurations such as the use ofMEMS steering and different trust beacon placement locations. Theexperimental parameters show performance using commercial off-the-shelfcomponents. Table 1202 summarizes these parameters, where not previouslydefined parameters X and Y are the test coordinate locations. For testcoordinates, a 1 m by 1 m plane at least 1 m away from a first trustbeacon (TB₁) in both x and y dimensions was used. This assumption isbased on the ZPU 104 unlikely being at large angles away from the trustbeacons in normal uses. The user height, that is the distance above theground in which the ZPU 104 sits, is assumed fixed for all results at1.654 m which is an approximate average human height.

FIGS. 13A-13B show two-dimension performance: predicted in graph 1302(a)with experimental performance in graph 1302(b), where graphs 1302(a-b)depicts 95% confidence ellipses. Results are shown using data collectedfrom the commercial off-the-shelf system components at four differentlocations: A (1, 1)m; B (2, 1)m; C (1, 2)m; and D (2, 2).

FIG. 14A depicts a graph 1402(a) exploring estimated position estimatesas a cumulative distribution function (CDF) of the mean square error(MSE) for different trust beacon placement heights and also the lateraldisplacement C between the trust beacons across the entire test spaceunder the baseline parameters. A small C distance results in weakerperformance regardless of height. The best performance is when the trustbeacon is placed at 1 m, and a difference of 0.654 m away from the user,which illustrates that placing the trust beacons at a plane not close tohuman height is ideal. This effect is due to angle measurements having,smaller effect on large angle deviations.

FIG. 14B depicts a graph 1402(b) showing different values of C and themaximum error in the test space at different trust beacon heights. Alongwith proving that a large height difference results in the bestperformance as concluded with graph 1402(a), graph 1402(b) shows theoptimal C displacement for a given trust beacon heigh. For around 0.5 mto 1.5 m displacement, the results are similar with no significantimprovement. Placing trust beacons between 0.5 m to 1.5 m away from eachother is thus ideal.

FIG. 14C depicts a graph 1402(c) showing the difference in finer qualitysteering when introducing MEMS steering in the yaw axis. The MEMSsteering does reduce position estimate errors. MEMS steering isdesirable for certain use cases as the MEMS actuators provide fasterconvergence in the form of fast steering speed and large field-of-view—aMEMS mirror scan module (Mirrorcle Technologies, Inc. Richmond, Calif.)has a scan rate of 1 Khz and a field-of-view of 40° which is relevantfor mobile devices and use cases requiring fast acquisition of trustbeacons with less user input. MEMS steering can be used for pitch aswell. Decreasing the noise on both pitch and yaw will likely result inperformance gains.

FIG. 15A depicts a graph 1502(a) showing the difference when using aknown trust beacon displacement, C, versus an estimated (est.)displacement, Ĉ. Each of C and Ĉ perform well depending on height. Thereis no fast holding rule to follow on whether a known or estimateddisplacement should be used as it is dependent on trust beacon location.Trust beacon location is known to the user-device when estimating. Inthe case of uncertainty, Ĉ will always ensure an estimate can be madeand is the better choice for displacement.

FIG. 15B depicts a graph 1502(b) showing results using data collectedfrom the experimental, commercial, off-the-shelf configuration at fourdifferent ZPU 104 locations: A (1, 1)m; B (2, 1)m; C (1, 2)m; and D (2,2) and a user height of 1.535 m. The trust beacons were placedrespectively at (0,0,2)m and (0,0.5,2)m. A small angle approximation wasused as the laser is placed adjacent to the Bose Frames reference axes.Experimental results show that accuracies are location dependent, asexpected, and consistent with simulations. For locations A and B, theMSE was less than 15 cm. However, for locations C and D, errors arelarger. Each test point, μ_(A), μ_(B), μ_(C), and μ_(D) was found tohave an MSE of less than 15 cm.

FIG. 16 depicts a graph 1602 showing position accuracies of less than 5cm under the baseline condition for three-dimensional positioning, animprovement over the 20 cm accuracy for two-dimensional positioning.Factoring in range from LIDAR greatly increased the positioning accuracyeven though additional costs are introduced to the positioning system.This is because LIDAR is a high accuracy methodology and provides betterestimates for radial distances than estimating based on the IMU 204measurements. This accuracy can be further improved with better rangingdevices, as a consumer grade LIDAR device was used here. This makes theZPU 104 a device that can be designed at different cost points. Forcoarser resolutions or inexpensive devices, the ranging sensor can belower quality than the LIDAR device used herein as a baseline. Sincetwo-dimensional positioning is a special case of three-dimensionalpositioning with a known height parameter, a range sensor-based solutioncan also be used for better resolutions in two-dimensional applications.Similarly, FIG. 17 depicts graph 1702(a) showing position accuracies of20 cm in simulated and experimental models without the use of ranging,and position accuracies of 5 cm with the use of ranging, while graph1702(b) shows position accuracies of less than 5 cm with a more precisezone-base positioning system.

FIG. 18A-18B depict graphs 1802(a) and 1802(b) showing transitivepositioning errors in a simulated and experimental context as explainedwith reference to the two-dimensional and three-dimensional cases. Nonew error rate is introduced in the transitive positioning application.Similarly, FIG. 19A-19B depicts graphs 1902(a) and 1902(b) showing theimpact of different transitive zone sizes. No new error rate isintroduced in this context either.

The subject technology enables mobility use cases in indoor positioningenvironments, similar to what is provided by global navigation satellitesystems (GNSS) services outdoors. These use cases include navigationthrough public spaces such as malls, warehouses, and hospitals, but alsospans position-based marketing, object labeling for augmented reality,and physical control of remote objects. Zone-based positioning enablesposition estimating of objects within a field of view of a user deviceor robot, after positioning the user device or robot relative a trustbeacon. Zone-based positioning is a scalable approach using low costcomponents and accuracy on the order of 10 centimeters or less asmeasured in three-dimensional mean square error.

All orientations and arrangements of the components shown herein areused by way of example only. Further, it will be appreciated by those ofordinary skill in the pertinent art that the functions of severalelements may, in alternative embodiments, be carried out by fewerelements or a single element. Similarly, in some embodiments, anyfunctional element may perform fewer, or different, operations thanthose described with respect to the illustrated embodiment. Also,functional elements shown as distinct for purposes of illustration maybe incorporated within other functional elements in a particularimplementation.

While the subject technology has been described with respect topreferred embodiments, those skilled in the art will readily appreciatethat various changes and/or modifications can be made to the subjecttechnology without departing from the spirit or scope of the subjecttechnology. For example, each claim may depend from any or all claims ina multiple dependent manner even though such has not been originallyclaimed.

What is claimed is:
 1. A zone-based positioning system comprising: afirst beacon positioned at a known position within an environment at agiven time, the first beacon having: a beacon optical detectorconfigured to receive an optical signal; and a beacon microcontroller,the beacon microcontroller capable of wireless communication, the beaconmicrocontroller configured to demodulate the optical signal from theoptical detector; and a zone positioning unit (ZPU) having: an opticalsource configured to transmit the optical signal, and use opticalcommunication to communicate with the first beacon via the beaconoptical detector; and a ZPU microcontroller capable of wirelesscommunication, the ZPU microcontroller configured to modulate theoptical source, wherein: the beacon microcontroller is configured toidentify and decode the optical signal after receipt by the beaconoptical detector to determine data related to a position of the ZPU, thedata including an orientation of the ZPU, the beacon microcontrollerfurther configured to wirelessly communicate with the ZPUmicrocontroller to convey information to the ZPU including the datarelated to a position of the ZPU and the known position of the firstbeacon; and the ZPU microcontroller is configured to determine aposition of the ZPU based on the information received from the firstbeacon.
 2. The zone-based positioning system of claim 1, wherein the ZPUfurther comprises a steerable system to direct the optical source toscan the environment for the first beacon as an optical target, thesystem including one or more of the following: micro-electromechanicalsystem, electro-optical system, holographic system, or plasmonicssystem.
 3. The zone-based positioning system of claim 1, wherein the ZPUfurther comprises a gaze-tracking system, the gaze-tracking systemconfigured to track an eye position of a user and direct the opticalsource based on the eye position of the user.
 4. The zone-basedpositioning system of claim 1, wherein the ZPU further comprises aninertial measurement unit to measure an orientation of the ZPU.
 5. Thezone-based positioning system of claim 1, wherein the ZPU furthercomprises a range sensor configured to measure a range from the ZPU toone or more of the following: the first beacon; a second beacon; or anobject.
 6. The zone-based positioning system of claim 5, wherein therange sensor includes one or more of the following: light and radiofrequency ranging via radio signal strength, ultra-wideband signals,millimeter wave, radio frequency, RADAR, time of flight, rotating laser,images, or LIDAR.
 7. The zone-based positioning system of claim 5,further comprising an object positioned within the environment, wherein:the ZPU is configured to transmit the optical signal to the object todetermine an orientation of the ZPU relative the object; the ZPU isconfigured to measure the range between the ZPU and the object; and theZPU is configured to determine a position of the object based on theorientation of the ZPU and the range between the ZPU and the object. 8.The zone-based positioning system of claim 1, further comprising atransitive device positioned within the environment, wherein: thetransitive device includes a transitive device optical detectorconfigured to detect the optical signal; and a transitive devicemicrocontroller capable of wireless communication, the transitive devicemicrocontroller configured to: identify and decode the optical signalafter receipt by the transitive device optical detector to anorientation of the ZPU relative the transitive device; and wirelesslycommunicate with the ZPU to convey data the orientation of the ZPUrelative the transitive device.
 9. The zone-based positioning of claim1, wherein the optical signal is modulated by the ZPU microcontroller toinclude data related to a position of the ZPU, the data includingreal-time orientation measurements of the ZPU.
 10. The zone-basedpositioning system of claim 1, further comprising a second beaconpositioned at a second known position within the environment, the secondbeacon having: a second beacon optical detector configured to detect theoptical signal; and a second beacon microcontroller, the second beaconmicrocontroller capable of wireless communication, wherein: the secondbeacon microcontroller is configured to identify and decode the opticalsignal after receipt by the second beacon optical detector to determinedata related to an orientation of the ZPU, the second beaconmicrocontroller further configured to wirelessly communicate with theZPU microcontroller to convey information including the data related toa position of the ZPU and the known position of the second beacon to theZPU; and the ZPU microcontroller is configured to determine a positionof the ZPU based additionally on the information received from thesecond beacon.
 11. The zone-based positioning system of claim 1, furthercomprising a plurality of beacons positioned at a plurality of knownpositions within the environment.
 12. A zone-based positioning systemcomprising: a first beacon positioned at a known position within anenvironment; and a zone positioning unit (ZPU) having: an optical sourceconfigured to transmit an optical signal to the first beacon; a rangesensor configured to measure a range from the ZPU to the first beacon;and a ZPU microcontroller configured to identify the position of thefirst beacon based on the optical signal, wherein: the ZPUmicrocontroller is further configured to compute a position of the ZPUbased on the range measurement from the ZPU to the first beacon, atransmission angle of the optical signal to the first beacon, and theposition of the first beacon.
 13. The zone-based positioning system ofclaim 12, wherein the first beacon further comprises an identifiableoptical signature, and wherein the ZPU microcontroller is configured todetect the identifiable optical signature based on the optical signal,and the ZPU microcontroller is configured to determine the position ofthe first beacon based on the identifiable optical signature and adatabase.
 14. A method of zone-based positioning comprising: providing afirst beacon at a known position within an environment, the first beaconhaving a beacon detector configured to receive a signal, the firstbeacon also having a beacon microcontroller capable of wirelesscommunication; providing a zone positioning unit (ZPU), the ZPU having asignal transmission device, the ZPU also having a ZPU microcontrollercapable of wireless communication, the ZPU microcontroller configured tomodulate the signal transmission device; directing a modulated signalfrom the ZPU; decoding the modulated signal after receipt by the beacondetector to determine data related to a position of the ZPU, the dataincluding an orientation of the ZPU; wirelessly communicatinginformation from the beacon microcontroller to the ZPU including thedata related to a position of the ZPU and the known position of thefirst beacon; and determining a position of the ZPU based on theinformation received from the first beacon.
 15. The method of claim 14,wherein: the beacon detector is a beacon acoustic detector configured toreceive an acoustic signal; and the signal transmission device is anacoustic source configured to transmit the acoustic signal.
 16. Themethod of claim 14, wherein: the beacon detector is a radio frequency(RF) signal detector configured to receive a RF signal; and the signaltransmission device is a RF source configured to transmit the RF signal.17. The method of claim 14, further comprising measuring a range using arange sensor on the ZPU, the range including a distance from the ZPU toone or more of the following: the first beacon; a second beacon; or anobject.
 18. The method of claim 14, further comprising: directing amodulated signal from the ZPU to an object to determine data related tothe ZPU position, the data including an orientation of the ZPU;measuring the range between the ZPU and the object using a range sensoron the ZPU; and computing a position of the object based on the datarelated to the ZPU position and the range between the ZPU and theobject.
 19. The method of claim 14, further comprising: providing asecond beacon at a second known position within the environment, thesecond beacon having a second beacon detector configured to receive asignal, the second beacon also having a second beacon microcontrollercapable of wireless communication; decoding the modulated signal afterreceipt by the second beacon detector to determine data related to aposition of the ZPU, the data including an orientation of the ZPU;wirelessly communicating information from the second beaconmicrocontroller to the ZPU including the data related to a position ofthe ZPU and the known position of the second beacon; and determining aposition of the ZPU based additionally on information received from thesecond beacon.
 20. The method of claim 14, further comprising providinga plurality of beacons positioned at a plurality of known positionswithin the environment.